As is generally known in the art, a direct seeder is a kind of agricultural machine which is used in such a way as to be pulled by a tractor. The direct seeder is constructed such that it can perform successive operations of forming furrows in the field, sowing seeds in the furrows, and covering the sown seeds with soil.
Referring to FIG. 1, the direct seeder comprises a main frame 11, a furrow forming unit 2 for forming seed furrows in the field, a sowing unit 30 for sowing seeds in the seed furrows, a covering unit 4 for covering the sown seeds with soil, and a fertilizing unit 5 for forming fertilizer furrows and putting fertilizer in the fertilizer furrows.
In the conventional direct seeder, since fertilizer receptacles 6a and seed receptacles 4a are installed at a relatively high position, in order to replenish fertilizer or seeds in the fertilizer receptacle 6a or in the seed receptacles 4a, a worker must stands on a support, whereby cumbersomeness is caused. Also, when replenishing fertilizer or seeds in the fertilizer receptacle 6a or in the seed receptacles 4a, because the operation of the direct seeder must be interrupted, the operational efficiency of the direct seeder decreases.
Further, due to the fact that the plurality of separate fertilizer receptacle 6a and the plurality of separate seed receptacles 4a are used, when replenishing fertilizer and seeds in the fertilizer receptacle 6a and in the seed receptacles 4a, the fertilizer and seeds must be divided into appropriate amounts in consideration of the capacity of each receptacle. Therefore, a replenishing time is lengthened, and the loss rates of the fertilizer and seed are increased.
Meanwhile, considering that the direct seeder is used in such a way as to be pulled by a tractor, means for leveling off or removing the traces of tractor wheels is needed. In the conventional direct seeder, while a screw conveyor is installed at the front end of the direct seeder to level off or remove the traces of the tractor wheels, the screw conveyor of the conventional direct seeder has a structure which is different from that of the present invention.